Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9675582 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2005 | 5 Pages |
Abstract
Dipole-dipole interactions in the most commonly used ferrofluids are relatively weak and there are only a few reports of chain formation in zero magnetic field. Here we report on the pronounced aggregation of a ferrofluid formed by maghemite nanoparticles (10Â nm in diameter), investigated by atomic force microscopy (AFM), small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS). The ferrofluid forms chain-like filaments independently of particle concentration. Furthermore, the ferrofluid forms self-assembled patterns, namely ordered superstructures, such as spirals, concentric rings and spokes (radially directed lines), when deposited on a substrate under a magnetic field. Our results reveal an unprecedented level of complexity in the self-assembly of magnetic nanoparticles. Further optimization of the working conditions could eventually enable the reproducible creation of three-dimensional magnetic structures with chosen architecture on submicron length scales.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Chiara Neto, Massimo Bonini, Piero Baglioni,